As promised, here is a summary of the presentation I gave last weekend to the Winter Meeting of the Iowa Prairie Network. I advocated using prairie restoration to increase the size and connectivity of fragmented remnant prairies and improve our chances of conservation success.

INTRODUCTION

Of all the threats to prairie conservation, habitat fragmentation is by far the most serious. Encroachment by invasive species and woody plants, chronic overgrazing, and broadcast herbicide/pesticide spraying are big threats to prairie species and communities too, but the fragmentation of grasslands into small isolated pieces makes all of those other threats even more dangerous and difficult to counteract.

When a large contiguous prairie landscape (left) is broken up into small isolated fragments of prairie surrounded by cropland, roads, and other human developments, prairie conservation becomes very difficult.

For example, pressure from both predation and invasive weeds and trees is usually most severe near the boundaries of a prairie. Because of their size, small prairies have very little area that is not exposed to these “edge effects”, so resident prairie species have no refuge from high predation rates and invasive species. In addition, the intensity of invasive species pressure in prairies with a lot of edge exposure increases the need for control efforts and makes excessive responses like broadcast application of herbicides more likely. Small prairies can also be more likely to be overgrazed because they’re not large enough to make up a significant part of an agricultural landowner’s income – and thus don’t get the careful management that larger grasslands would.

Most importantly, small prairies simply aren’t large enough to provide the physical space and population sizes needed to sustain many species of plants, insects, and animals. Small populations, whether of birds, butterflies, or wildflowers, are much more vulnerable to local extinction because a disease, weather event, management treatment, or other stressor can easily affect the entire population. If one of those small populations is wiped out by a particular event (or series of events), the only chance of that species reappearing is through recolonization from nearby prairies – but in a small AND isolated prairie, that’s unlikely to occur.

The fragile nature of small populations in tiny isolated prairies makes those prairies extremely difficult to manage for biological diversity. Every management decision is going to favor some species at the expense of others. Because small populations aren’t very resilient, it’s easy for them to be much more strongly affected by individual management decisions than they would be in a larger prairie where populations are larger and management treatments are less likely to spread across the entire site (leaving refuges for species to recolonize from, if necessary).

Here’s a goofy but perhaps useful analogy. Imagine that prairie conservation is like trying to catch hundreds of pieces of popcorn falling from the sky. In order to save a species (a piece of popcorn), you have to catch it as it falls. Managing small prairies is like trying to catch all of that falling popcorn in a coffee cup. Because the cup is small, the task is impossible. If you move one way to catch some popcorn pieces, you’ll miss others. And even if you’re really agile, your cup isn’t big enough to hold all the popcorn anyway – so you’re doomed to failure before you start.

Conserving prairie species in tiny prairies is like trying to catch falling popcorn in a coffee cup. (sort of)

The difficulty of maintaining a prairie ecosystem in small isolated fragments leads to feelings of frustration and helplessness among prairie managers. It also leads to conflicts between managers and advocates of various prairie species/groups. For example, some rare prairie butterfly experts advocate managing prairies without the use of prescribed fire because fires can destroy larvae, and a fire that burns an entire small prairie can completely wipe out the whole population of some rare butterfly species. Avoiding the use of fire may make sense for those few butterfly species, but what about all the other species that would suffer from a lack of fire? Do we manage some prairies exclusively for butterflies – and whatever other species can survive with that management? I don’t think we have enough prairies left to start managing each of them for individual species or groups of species. And yet, the threat of losing butterfly species is real – and important. Unfortunately, the underlying issue is not whether or not fire should be used to manage small prairies, the issue is that rare butterfly populations are small because the prairies they rely on are small and isolated.

Ok, so small isolated prairies create all kinds of problems for conservation, but they’re all we have in many places, particularly in North America’s tallgrass prairie region. What do we do about it? One choice is to continue trying to catch popcorn in our coffee cups, knowing that we will eventually fail to save many species. The second choice is to make more prairie – and enlarge and reconnect some of the existing remnant (pre-existing and unplowed) prairies to give ourselves a better chance of conservation success. In other words, we can turn our prairies into something more like a wading pool – instead of a coffee cup – so that it becomes easier to catch the falling popcorn.

It's much easier to catch falling popcorn (conserve prairie species) with a wading pool (large prairie) than with a coffee cup (small prairie).

Our ability to restore (reconstruct) prairies by harvesting seeds and converting cropland to diverse plant communities has come a long way since its early days. Numerous local pioneers have worked out successful methods of seed harvest, site preparation, planting, and weed control, and know how to establish hundreds of acres of restored high-diversity prairie each year. Those prairies can contain hundreds of plant species, and can support many of the insects and animals found in remnant prairies. However, there’s still much to learn about the extent to which restoring prairie around and between remnants increases population viability for those species, and we still need to identify those species that can’t make the jump between remnants and restorations – and find out why. That said, we know enough to start using restoration to make prairies larger and more connected (and we don’t really have a lot of other options.)

It's not feasible to restore entire landscapes to prairie, but if we can strategically restore parcels of land around and between remnant prairie fragments (right), we can greatly increase our chances of conserving prairie species.

.

GETTING IT DONE

If we’re going to use prairie restoration to make a real difference in conservation, the first step is to get better at strategically targeting our restoration efforts around and between existing small and isolated prairies. This is being done at a few sites, but the vast majority of prairie restoration work is scattered piecemeal across the landscape. Because restored prairie doesn’t compete economically with rowcrop agriculture, prairie restoration on privately-owned land generally happens when an individual landowner makes it a high priority and/or when Farm Bill programs like the Conservation Reserve Program (CRP) or other similar cost-share programs can help close the financial gap. The agencies that administer those cost-share programs typically have little capacity to go out in the field and sell the programs to strategically-located landowners. Instead, they usually sign up the people who come to them (and there are usually enough of those to use up the available money). As a result, the location of prairie restoration depends more upon which landowners express an interest than where their property is located.

Another issue we need to address is the way in which these cost-share program funded restorations are designed. For the most part, agency guidelines allow only enough funding per project to pay for a low-diversity seed mixture. This is largely because the continued funding of these programs by Congress depends heavily on the total number of acres enrolled each year – making it necessary to spread the available money broadly instead of focusing it on a few high-quality projects. While low-diversity seed mixtures can help species like grassland birds, many other species (including pollinators) rely on a high diversity of plant species, and the overall ecological function of a high-diversity prairie is much higher than that with only a few plant species.

Improving the strategic location and quality of prairie restoration will mean taking several approaches. In some cases, conservation groups can simply attempt to purchase tracts of land around and between remnant prairies and restore them. While effective, this can be difficult and expensive. However, if fundraising efforts are targeted toward our highest priority remnant prairies and situations in which the potential for success is high, even small parcels of conservation ownership can be helpful.

In order to bolster the viability of more than a few high priority prairies, however, private lands are going to have to be a large part of the strategy as well. Because agencies like NRCS (Natural Resources Conservation Service) don’t usually have the ability to direct market their programs to landowners, other conservation groups can help by approaching owners of key land parcels and discussing the potential for conservation program enrollment with them. Finding a few interested landowners and helping them enroll can pay big dividends because one successful project often leads to other enrollments by neighbors who see the aesthetic and conservation benefits from across the fence.

Influencing the design of restoration projects funded by NRCS and other agencies is often possible as well. For example, the biggest obstacle to using higher-diversity seed mixes is the cost. If conservation groups can help find additional funds to increase the number of plant species in seed mixes – and if the landowner helps push for it – restoration quality can improve dramatically. In addition, those conservation groups can help by building and maintaining long-term relationships with enrolled landowners. Helping landowners understand the benefits of their restored land, and how it fits into a larger conservation strategy, will improve the chances that the restored prairie will be carefully managed (and even retained as prairie) as the years go by.

Prairie conservation is difficult. In highly fragmented landscapes it can sometimes seem nearly impossible. However, we have the ability to greatly improve our chances of success by converting isolated prairies from coffee cups to wading pools, so to speak. Success will depend upon a concerted and collaborative effort between conservation groups, government agencies, and private landowners, but it is possible. Surely we can agree that prairies are worth the effort?

Epilogue: How do we measure the success of prairie restoration?

I’ll deal with this more extensively in an upcoming post, but a brief mention is important here. When using restoration as a strategy to expand and re-connect remnant prairies, the objective is not to copy the existing remnants (or some historical version of them) but to complement them with restored plant communities that allow the plants, insects and animals within the remnants to have larger and more interconnected populations. Because of this, evaluating differences between remnant and restored communities should not be the primary measure of success.

There are a number of research papers that have shown differences between the relative abundance of individual plant species, levels of soil organic matter, composition of the insect and soil fauna communities, etc., between remnant and restored prairies. These papers often interpret those differences as indicators that we’ve not yet restored “real” prairie. I think that kind of research is interesting, but largely misses the point. If our objective is to replicate existing or historic prairie we will surely fail – but why would we expect otherwise? Trying to recreate exact copies of ecological communities that formed over thousands of years – and doing so on degraded soils, in different climatic conditions, and under pressure from vastly different invasive species and other threats – is not a recipe for success.

However, when we look at restoration as a tool for improving the viability of existing remnants, the most important measures are those that evaluate whether or not prairie populations and communities are larger, more interconnected, and more resilient. Those are difficult things to evaluate, unfortunately, and we need develop better measures than we currently use. That means we’ll need to shift our current research focus from identifying differences between remnants and restorations to investigating how well they interact with each other.

Share this:

Like this:

LikeLoading...

Related

About Chris Helzer

Chris Helzer is an ecologist and Eastern Nebraska Program Director for The Nature Conservancy. He supervises the management and restoration of approximately 4,000 acres of land in central and eastern Nebraska - primarily along the central Platte River.
Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press.

Chris,
I was on an Earthwatch research project years ago investigating this very thing, only with mountain lions. The size of individual cats’ ranges was decreasing in southern Idaho due to expanding farmland and the project was trying to determine the minimum range size before an individual cat would move somewhere else. They are very loath to cross farmland to use additional range, preferring one large tract for their habitat.

Realizing that prairie edges will always be threatened by their neighbors, human and otherwise, do you have an estimate of size for an individual prairie where the core acreage will be self-sustaining? Obviously irregular shaped plots confuse the estimate but assume a regularly shaped prairie. I’m asking because that might be a piece of data you can approach landowners with to show how much a contribution they should consider and the leverage that additional land will have on improving the core prairie. Instead of land that would elongate a strip of prairie it might be more effective to get two plots, one on either side, to make a wider strip that would offer more protection to the core by being transition zones.

Mel, your question is one of the most important facing prairie conservation right now, and I’m frustrated that I can’t give you a very good answer. We can make some estimates based on what we think grassland birds need, but beyond that we really don’t know. It may be that plant species need smaller areas than birds do (or it could be the opposite because of genetic interaction needs). Same questions about insects and other prairie animals.

If you pinned me down, I’d make a wild guess that 640 acres of land would be about as small as you’d want to go if you were trying to maintain effective populations sizes for at least some of the smaller prairie species. But I’d feel way better about a landscape of 3-5,000 acres or more. However, as I said, I’m making these guesses without any real data to back me up. We’ve got a research program going on in SE Nebraska aimed at gathering info to help address these questions, but it’s going to take a long time to get very far, and it’s going to need lots of other people in other landscapes doing similar research to really get some answers.

Chris,
Superb post as always! In your opinion which do you place a greater premium on when restoring adjacent to a remnant local provenance or diversity. Example if you are trying to establish an uncommon plant (prairie lily is a good example here in southwest Minnesota) that only is commercially available from southern Wisconsin, would you omit that species (the seed would be coming a couple hundred miles) or include it for the sake of diversity in the seed mix, especially if there are already prairie lilies in the remnant, albeit rare? A problem I am still grappling with, as seeding a couple hundred acres without it and other tough to collect species is in my opinion reducing the habitat value of the restoration.

Jeff – great question, and a difficult one to answer. One answer is that it depends upon how important prairie lily is to your objectives. If it’s near the top of your priorities, than I’d work to get it.

Another way to look at it is this – Are there natural populations near your prairie (within 10 miles?). If not, I’d feel a little less worried about bringing in non-local genetics because you’d have a slim chance that your “introduced” plants wouldn’t have much opportunity to interact with local plants. If you do have nearby plants, are there opportunities to harvest seeds from them? If you have to go outside your immediate local area, the closest locations would present the lowest risk, so prioritize that way. Also, getting plants from the east or west is generally better than going north or south because differences in latitude can be problematic to seasonal needs of plants (they may bloom at the wrong time for pollinators – or may not be able to complete their life cycle in a shorter growing season, etc.).

I guess to summarize (and there are few data to support these answers because we just don’t have much research to go on) I’d say that you want to be conservative. Get seed from as close to you as possible, but if the species is absent from your area, but historically there, I’d go to the nearest possible location to get seed. The other disclaimer is that I’d definitely talk to someone you respect in SW MN about the issue to see if they have more specific information that could help you.
– Chris

Jeff – as I reread your question, I realized that you mention that you’ve already got lilies in your remnant, so I would shape my answer a little differently. In that case, I’d try to get some seed from those lilies – or others within 10-20 miles or so, if possible – and start those by seed or seedling in your restoration. I’d be very cautious about bringing in non-local genetics in your case. I’d also be careful not to steal all the seed from all the plants in your remnant! Maybe take 10% a year or so, in order not to impact their populations more than necessary. You should talk to someone in MN who’s got experience with prairie lily establishment to see whether it’s better to try direct seeding or to grow out seedlings and plug them in later.

Nice work on this post! I have not seen the popcorn analogy used before – a sign of your ingenuity!

As daunting as the task of prairie reconstruction is, I can think of some even more challenging; establishing a convincing economic reality that the North American prairie complex is worth saving followed by the political muscle to make it happen.
Most of those isolated remnants, and the lands that surrounds them, have no long-term protection. CRP is just temporary. The federal programs (WHIP, LIP, F&W Partners, etc.) that provide matching funds for at-risk ecosystems come with long-term, unfunded maintenance agreements so most landowners balk at them. Property tax land use polices often penalize (financially) landowners who want to protect their prairie remnants. Protected natural lands held by state governments, land trust, and big NGOs continue to degrade with lack of management. And the list goes on. To date, there has been no room in capitalism for conservation. This, no doubt, has to change for prairie ecosystems to survive. I have faith in the scientists and practitioners involved in prairie restoration, but convincing society that prairies are worth saving gives me great anxiety.

I tend to think that there are three choices. 1. We do nothing. 2. We pay landowners a subsidy for owning high-quality prairies as long as they manage them well (Very difficult to administer, because who’s to judge quality of management?) 3. We raise the level of the general consciousness about prairies among the public so they’re more roundly admired – in other words we make it a privelege and honor to own a prairie.

I don’t think we can make prairies pay for themselves. Subsidies have some allure, but that is just another policy that can be changed – and it’s expensive. I really think #3 is the best option, I’m just not sure how to go about it. Among a few of us here, we’ve been throwing around the idea of building some kind of recognition program for owners of important natural areas (similar to Natural Area Registry programs elsewhere) but really playing up the part about how rare these areas are and what an honor it is to own one (and a responsibility to society to manage it well). I’m not sure it’s the best answer, but it might be a next step for us.

Chris: I love the popcorn image. Would you mind if I borrow it to use in a talk I have to give here in Canada on grassland conservation? I will be sure to say it comes from a brilliant young ecologist in Nebraska named Chris Helzer. If that is not enough butter I am also adding your blog to the recommended blogs on mine, Grass Notes–and later this week will post something about two of your recent pieces that have really resonated with me. (I am a bird guy but appreciated what you said about birds often being not that helpful as an indicator of ecological health in grassland. It needed to be said.)

Recognition for landowners from leading conservation groups is a good idea that I think would be well received. It is also one that is in your (groups like the Nature Conservancy) ability to execute without any dependencies on law makers. I like the focus on private landowners, as opposed to government ownership, as it will weather the political climate much better.

I would also like to see property tax relief for private landowners who own and care for prairie remnants and any adjacent reconstructed prairie land. I have been meaning to research Minnesota’s law a bit more carefully as I know they have some programs. Here is the link. http://www.dnr.state.mn.us/prairierestoration/index.html

To qualify for the property tax relief would require active ecological management and permanent land protection. I feel the tax relief should be equivalent to the tax rate classification of low-grade agriculture land as oppose to tax exempt. Again, I feel this would weather the political climate much better. In many cases, the property tax collected would not be significantly different pre and post tax relief but it would prevent reclassification of the land to a much higher tax rate.

We need to acknowledge that private landowners invest significant resources into their ecological restoration efforts. Examples of these resources include purchasing land, hiring professional contractors, the landowner’s time and labor, sizable investment in capital equipment, land management endowment, legal protection fees, loss of income from commodities (crops, timber, etc.), and many other on-going land costs such as property taxes. In many cases, they are also going against the tide of local culture and as a result stand alone and isolated in their core beliefs.

Publicly recognizing these landowners would have value twofold. For the landowners themselves, being acknowledged, by leaders in conservation, for their strong land ethic and their wiliness to invest their own treasure into protecting a piece of natural heritage would strengthen and reenergize their commitment to restoration. The public recognition, along with an award-winning “energized” landowner, will hopefully inspire other landowners to follow suit. Combining this with the conditional property tax relief will have the benefit of convincing landowners that the public also cares about prairie protection and that they are not as alone and isolated as they might have thought.

Glad to hear that others are thinking about, and care about, these issues!

Excellent topic and probably one of the most important things to consider when talking about management and restoration on a larger scale. Starting out with a wading or even swimming pool likely means the odds of preserving all the pieces and parts (popcorn) is much more likely than starting out with the coffee cup or thimble, and trying to trade it in for the wading pool through aggressive reconstruction efforts. However, I recognize that we work and volunteer where we live and where we can see our efforts and results on a personal and frequent basis. So statistical odds will mean there are more prairie enthusiasts where the densest human populations are located, and also the most development and fragmentation of prairies exists. There is a greater sense of urgency to conserve the last few pieces that are named and numbered. It also means that politically and socially, you may be more likely to garner support for conservation of the last native prairies to be found.

My main point I am winding up to, is that prairie enthusiasts who live where native prairie only remains in coffee cup or thimble size pieces play a very critical role in conserving what remains. They may have to watch popcorn hit the ground, but the prairie that remains educates and inspires many. Their hands on actions allow themselves and others to get deep into prairie reconstruction and gain a strong appreciation for prairies that can be shared with many. They can also play a crucial role and provide significant political support for conservation of native prairies in locations where prairies still exist at larger landscape level scales (wading or swimming pool size). I live and work in northeast South Dakota and there are still large blocks of native mixed grass prairie and tallgrass prairie that have not been plowed. Much of that is due to the fact that the glacial soils have not been considered as good farmland in the past and the fact that many cattlemen and cattlewomen remain on the land and see the benefits of leaving native prairie with the roots pointing down. That could all begin to change within a generation as many ranchers retire. Significant changes in farming equipment, advances in crop technology, and the shift from family operations to corporations is occurring across not only South Dakota, but all of the remaining tall and mixed grass prairie States. My paradigm of where I thought native prairies were secure is changing rapidly.

Core pieces of prairie owned and managed by federal and state agencies, and organizations such as TNC, combined with perpetual conservation easements purchased from willing private landowners appears to be the model that has the greatest chance to conserve tall and mixed grass prairie from the plow on a landscape scale. The piece that is often missing in the model is aggressive prairie reconstruction/restoration on degraded sites or plowed sites embedded in the landscape. This is the model that the Small Wetlands Acquisition Program ( http://www.fws.gov/refuges/smallwetlands/ ) which the US Fish and Wildlife Service administers, has used since the 1960s. It was started as a way to conserve waterfowl and migratory bird habitat, and by chance or luck, that means wetlands embedded in tall and mixed grass prairie. Other organizations are pursuing similar efforts. So maybe the new slogan I am promoting is “Think global, act local, and support regional” if you want your prairie reconstruction and management efforts to have the best chances to catch all the popcorn you can.

Tom, you put it perfectly. You’re absolutely right about the correlation between number of prairie enthusiasts and amount of remnant prairie left on the landscape. As I go east, I see all kinds of prairie enthusiast and nature groups set up to appreciate and conserve prairies. In Nebraska, South Dakota, and other states in the western tallgrass and mixed-grass prairie regions we’ve got some fantastic prairie lands remaining, but few fan clubs… I suppose that makes sense sociologically. (at least to an ecologist)

So how do we fix that? We need to grow the fan base in the west and draw help from the enthusiastic base in the east. How? Mike Forsberg’s got an upcoming documentary on public television (based on his recent book about the Great Plains) that will help raise awareness, but what’s the action step? What do we want people to actually do? That’s where I’m struggling.

It’s not that I don’t want to get involved. But I don’t want to get involved. I have opinions on the matter, but it doesn’t appear to me that more opinions would help. I’m not sure data would help either, for that matter. Maybe time will.

Chris,
Thanks for that estimate. I wonder at times when I see the brief swaths of roadside devoted to “prairie restoration” whether that’s even worth the time. Probably looks nice to people speeding by but most likely does nothing for the grand scheme.

What you’re talking about is making prairies more marketable so people respect and appreciate them more. Certainly protection by responsible ownership and publicity of such is the best way. As mentioned, tax breaks for owners who manage prairie is an incentive. My belief is people will behave according to their perceived reward, whether that’s a beautiful scene, less taxes or just gaming the system.

One of the best ways to expand the amount of something is to market it’s popularity. A writer once mentioned the best way to increase the numbers of bald eagles was to start selling great tasting eagleburgers. Not endearing to a conservationist’s heart but supply will catch demand. If prairies were sexy people would demand having them, don’t you think? Just a matter of figuring out a marketing/publicity plan to give them that aura. “Prairies do it in the open”?